class Container {
    static of(value){
        return new Container(value);
    }

    constructor(value) {
        this._value = value;
    }

    map(fn){
        return Container.of(fn(this._value))
    }

}

class Maybe {
    static of (x) {
        return new Maybe(x)
    }
    
    isNothing () {
        return this._value === null || this._value === undefined
    }

    constructor (x) {
        this._value = x
    }

    map(fn){
        return this.isNothing() ? this : Maybe.of(fn(this._value)) 
    }
    
}

module.exports = {Maybe,Container}